Viewing CO2 laser with LWIR camera - DON'T!!!

[MadTux]

'normal' people use LWIR sensors to check the profile of an expanded beam.

Wouldn't risk my expensive IR camera for that, if good old thermal paper from local supermarket cashier works just as well   

[Ultrapurple]

@MadTux - I think I may not have explained clearly enough what I was trying to achieve. I was looking, at a distance, side-on to the laser beam to determine whether the beam was visible to the camera in the same way one can see a visible light laser beam in a slightly smoky atmosphere. There was no attempt at beam profiling and no intentional interception of any significant part of the beam power.

Think in terms of a far-infrared version of the blue beam seen in the grape pictures earlier in this thread.

I'm well aware that I'd need to attenuate the laser beam (technically, reduce the power per unit area) by an extreme amount before it was remotely safe to have it incident on a microbolometer, and only slightly less so if using a thermal camera to view a beam incident on a surface (eg for profiling).

[Ultrapurple]

I may have some good news to report.

After I initially damaged this camera I was, as you may imagine, gutted. So much so that I didn't actually use it for several months: I couldn't bring myself to see the awful result of my naivety. But recently I got it out again and was surprised to discover that there had been a certain amount of 'self-healing' on some of the damaged pixels. So much so that it was now possible to run the Dead Pixel routine (which previously just threw up its hands in horror at the damage). The result is that I now have a useable camera again! RESULT!

The first image shows the original damage (the two areas centre bottom - ignore the other slight blemishes); the second is a representative image taken some four months after the damage and after a successful Dead Pixel run.

[Ultrapurple]

That's fascinating (and sad at the same time). But it does suggest that it might be worth befriending the local phone repair shop and asking them for any dead AMOLED screens that they replace.

[Ultrapurple]

I forgot to say, in the second picture I'm not the one on the right. Draw your own conclusions as to whether I'm the one on the left.

[CatalinaWOW]

@MadTux - that's an interesting point. You probably wouldn't need anything like precision aiming; even a (say) 40W CO2 laser with a beam expanded to a 30 degree or more cone would probably be bright enough to give a microbolometer something to think about. 

Before anyone rushes out to try this, I should point out that aiming lasers of any kind at aircraft, vehicles or people is a very bad idea and in must jurisdictions is punishable by a hefty fine and/or imprisonment. But I guess if your cargo is a hundred tons of narcotics you've already realised that getting caught would probably spoil your day.

@Fraser - looking at the end of that video when the chap was shining the laser into the sky reminds me of a night many years ago when I had a 250mW or so green DPSS laser that I aimed skywards during a several-day amateur radio exhibition. As you'd expect, it formed a bright pillar of light reaching to the heavens. What I didn't expect was someone asking, in all seriousness, if I would let them string an aerial wire from the far end 

Lasers are quite powerful, but not omnipotent.  Your 30 degree beam at 1 kM illuminates an area of roughly .2 sq kM, or 2E9 sq cm.  Power density is then about 2E-8 W/sq cm.  Given a nominal aperture of the camera of about 100 sq cm you are depositing a couple of microwatts (less transmission losses) on the focal plane.  Very bright but not necessarily damaging.  And that is actually a fairly large aperture camera.

Of course if you don't spread the beam so much the danger zone grows much larger.